It is disclosed that the melinjo components have various biological actions. Patent document 1, Patent document 2 and Non-Patent document 1 disclose an antioxidant action, an antibacterial action, a lipase inhibitory action and an amylase inhibitory action of gnetin C, Non-Patent document 2 discloses an angiogenesis suppressive action and an antitumor action of gnetin C, Non-Patent document 3 discloses an antitumor action of gnetin C, Non-Patent document 4 discloses an apoptosis induction action of gnetin C in human leukemia cells, Patent document 3 and Non-Patent document 5 disclose an immunostimulating action of a melinjo extract, Non-Patent document 6 discloses an antibacterial action of a melinjo extract, Patent document 4, Non-Patent document 7 and Non-Patent document 8 disclose an anti-obesity/diabetes improving action of a melinjo extract, Patent document 5 and Non-Patent document 9 disclose a tyrosinase inhibitory action and a melanin biosynthesis inhibitory action of gnetin C, Non-Patent document 10 discloses a vascular aging suppressive action of a melinjo extract, Patent document 6 discloses anti-aging by a sirtuin activating action of gnetin C, Patent document 7 discloses an angiotensin converting enzyme inhibitory action of a melinjo extract, Non-Patent document 11 discloses a serum uric acid level lowering action of a melinjo extract, Non-Patent document 12 discloses a periodontal disease exacerbation preventing action of a melinjo extract, Non-Patent document 13 discloses an atrophic skin suppressive action, Non-Patent document 14 discloses an immunomodulating action of a melinjo extract, and Non-Patent document 15 discloses an AMPK phosphorylation elevating action of a melinjo extract in liver of a newborn female child of a fructose excessively ingested pregnant rat. Further, safety of a melinjo extract is also recognized since the melinjo extract shows a high density lipoprotein (HDL) cholesterol increasing action and a uric acid level lowering action without showing any abnormalities in a toxicity test in rats (Non-Patent document 16) and a safety test in humans (Non-Patent document 17), and exerts no influence on the anticoagulant activity of a hepatic metabolizing enzyme cytochrome P-450 and warfarin (Non-Patent document 18). Further, it is reported that gnetin C exerts a more antiproliferative effect than that of medicinal products on leukemia cells of a patient (Non-Patent document 19).
The main component contained in endosperm of a melinjo seed is gnemonoside A as a glycoside of gnetin C represented by the following formula (2), and it is already disclosed that the component showing the actions described above is gnetin C as an aglycon represented by the above-described formula (1). Patent document 1 discloses a production method of a Gnetaceae extract comprising aging at ordinary temperature to 70° C. utilizing generation of gnetin C by an enzymatic reaction during the aging, and since the content of gnetin C in the Gnetaceae extract is less than 15%, the amount of intake thereof tends to increase for obtaining the various effects described above. Promotion of an enzymatic reaction in aging is not disclosed and also is not suggested in any of the above-described documents. Further, the method for investigating generated state is only a qualitative test by ultraviolet absorption spectrum and thin layer chromatogram (TLC).
(It is gnemonoside A when R1 and R2 represent a glucopyranosyl group, gnemonoside C when R1 represents a glucopyranosyl group and R2 represents hydrogen, and gnemonoside D when R1 represents hydrogen and R2 represents a glucopyranosyl group, in the formula.)